1. Field of Invention
This Invention relates to the Plastic Recycling Industry for quality control in detection of clear polyvinyl chloride (P.V.C.), bottles ground with clear polyethylene terephthalate, (P.E.T.), bottles.
2. Description of Prior Art
P.E.T. (polyethylene terephthalate) as clear plastic containers.
P.V.C. (polyvinyl chloride) as clear plastic containers.
Both materials are post consumer, curb side recycled products.
To my knowledge, except for visual inspection under ultra violet black light and dying the material in question with a solvent to etch the P.V.C. with dye and then visual counting the dyed chips by hand, done only as a means of rejecting entire loads of material if any P.V.C. is found. To this date there has been no method to detect and remove P.V.C. grinds from P.E.T. grinds. I have been advised that the two products being accidently ground together is the greatest problem in the plastics recycling program.
A single P.V.C. bottle in a 1000 lb Gaylord box results in approximately 350 parts per million of contamination, the accepted level is 0 parts per million. If the material goes undetected and is subjected to the process temperature of P.E.T. it turns black and can release toxic fumes that have paralyzed people.
Until now no one has developed a method to detect and remove the P.V.C. contaminant. Contaminated material can not be used for its first intended purpose.
The apparatus I wish to protect by patent and bring to market does and will lead to equipment that will allow the detection and removal of P.V.C. from P.E.T., in grind and whole bottle separation, it is not an expensive process and no additives or harmful radiation are needed.
In March of 1993 as stated in Disclosure Document No. 341610 filed Oct. 25, 1993 and Disclosure Document No. 338121 filed Sep. 3, 1993 after producing a load of ground P.E.T. material and having it rejected for having P.V.C. ground in it and being told that if we observed the two materials under ultraviolet black light that there was a slight difference in the two materials color. After viewing the material I noticed that polyethylene terephthalate appeared blue color and polyvinyl chloride appeared an amber/gold color. At that time I began to test for ways to electronically detect the color differences caused by the different materials in ultraviolet black light.